Table 2.
Characteristics of patients with and without HLA-DSA.
| ABMRhDSApos (n = 38) | ABMRhDSAneg (n = 14) | p-value | |
|---|---|---|---|
| Recipient age (years) [mean (SD)] | 47.8 (15.7) | 46.4 (14.2) | 0.76 |
| Recipient gender (female) (n, %) | 20 (52.6) | 7 (50) | 1.00 |
| Recipient race (caucasian) (n, %) | 34 (89.5) | 12 (85.7) | 0.46 |
| Type of donor (deceased) (n, %) | 36 (94.7) | 10 (71.4) | 0.038 |
| Donor age (years) [mean (SD)] | 45.5 (18.9) | 46.9 (13.7) | 0.80 |
| Underlying renal disease | |||
| − Glomerular disease (n, %) | 5 (13.2) | 6 (42.9) | 0.10 |
| − SLE and other autoimmune disease (n, %) | 2 (5.3) | 0 (0) | |
| − Diabetes (n, %) | 1 (2.6) | 0 (0) | |
| − Other (n, %) | 30 (78.9) | 8 (57.1) | |
| Retransplantation (n, %) | 14 (36.8) | 2 (14.3) | 0.18 |
| Peak CDC cPRA (%) [mean (SD)] | 14.2 (26.2) | 0.6 (2.4) | 0.003 |
| Pretransplant HLA antibodies (SAB) (yes) (n, %)* | 25 (78.1) | 3 (42.9) | 0.08 |
| HLA mismatch Class I (A/B) [mean (SD)] | 2.8 (1.0) | 2.6 (1.0) | 0.52 |
| HLA mismatch Class I (C) [mean (SD)] | 1.3 (0.7) | 1.1 (0.8) | 0.25 |
| HLA mismatch Class II (DR) [mean (SD)] | 1.4 (0.5) | 0.7 (0.6) | <0.001 |
| HLA mismatch Class II (DQ) [mean (SD)] | 0.9 (0.7) | 0.7 (0.7) | 0.41 |
| Antilymphocyte induction (n, %) | 9 (23.7) | 3 (21.4) | 0.28 |
| Delayed graft function (n, %) | 16 (42.1) | 3 (21.4) | 0.21 |
| Acute cellular rejection <3 months after KT (n, %) | 5 (13.2) | 6 (42.9) | 0.08 |
| Clinical characteristics and graft function at biopsy | |||
| Surveillance biopsy (n, %) | 18 (47.4) | 4 (28.6) | 0.34 |
| Biopsy time after KT (months) [median (IQR)] | 44 [14–99] | 74 [15–220] | 0.22 |
| Time biopsy to serum (days) [mean (SD)] | 30 (78) | 20 (61) | 0.66 |
| Serum creatinine (mg/dl) [mean (SD)] | 2.01 (1.0) | 1.70 (0.6) | 0.30 |
| Estimated GFR (ml/min) [mean (SD)] | 44.8 (25.5) | 45.8 (19.1) | 0.89 |
| Urine protein/creatinine ratio (mg/g) [median (IQR)] | 413 [170–1189] | 695 [406–1,174] | 0.27 |
| Immunosuppressive treatment at biopsy | |||
| Prednisone (n, %) | 30 (78.9) | 9 (64.3) | 0.30 |
| Calcineurin inhibitors (n, %) | 27 (71.1) | 12 (85.7) | 0.47 |
| Mycophenolic acid (n, %) | 32 (84.2) | 11 (78.6) | 0.69 |
| mTOR inhibitors (n, %) | 14 (36.8) | 3 (21.4) | 0.34 |
| Follow-up | |||
| Graft loss (n, %) | 19 (50) | 8 (57.1) | 0.76 |
| Death-censored graft loss (n, %) | 15 (39.5) | 6 (42.9) | 1.00 |
| Time after biopsy (months) [median (IQR)] | 61 [21–85] | 55 [27–76] | 0.87 |
| Histological features of ABMRh | |||
| Percentage of glomerulosclerosis [mean (SD)] | 18.4% (17.5) | 18.8% (18.4) | 0.95 |
| Glomerulitis (g ≥1) (yes, %) | 30 (78.9) | 12 (85.7) | 0.71 |
| g0 | 8 (21.1) | 2 (14.3) | |
| g1 | 16 (42.1) | 4 (28.6) | 0.58 |
| g2 | 10 (26.3) | 5 (35.7) | |
| g3 | 4 (10.5) | 3 (21.4) | |
| Peritubular capilaritis (ptc ≥1) (yes, %) | 31 (81.6) | 9 (64.3) | 0.27 |
| ptc0 | 7 (18.4) | 5 (35.7) | |
| ptc1 | 21 (55.3) | 5 (35.7) | 0.18 |
| ptc2 | 10 (26.3) | 3 (21.5) | |
| ptc3 | 0 (0) | 1 (7.1) | |
| Microvascular inflammation (g + ptc ≥2) (yes, %) | 31 (81.6) | 12 (85.7) | 1.00 |
| C4d positivity (yes, %) | 17 (44.7) | 6 (42.9) | 1.00 |
| C4d0 | 20 (54.1) | 8 (57.1) | |
| C4d1 | 4 (10.8) | 2 (14.3) | 0.07 |
| C4d2 | 3 (8.1) | 4 (28.6) | |
| C4d3 | 10 (27.0) | 0 (0) | |
| Chronic transplant glomerulopathy (yes, %)# | 20 (58.9) | 9 (69.2) | 0.74 |
| EM CTG or PTCML (yes, %)# | 28 (82.4) | 9 (69.2) | 0.43 |
| Arteriolar hialinosis (ah ≥1) (yes, %) | 18 (47.4) | 6 (42.9) | 0.76 |
| Arterial intimal fibrosis (cv ≥1) (yes, %)# | 18 (52.9) | 6 (50) | 1.00 |
| Interstitial fibrosis (ci ≥1) (yes, %) | 35 (92.1) | 14 (100) | 0.56 |
| Tubular atrophy (ct ≥1) (yes, %) | 32 (84.2) | 14 (100) | 0.17 |
| Tubulitis (t ≥1) (yes, %) | 8 (21.1) | 0 (0) | 0.09 |
| Interstitial inflammation (i ≥1) (yes, %) | 6 (15.8) | 0 (0) | 0.17 |
| Intimal arteritis (v ≥1) (yes, %)# | 1 (3.1) | 0 (0) | 1.00 |
ABMRh, antibody-mediated rejection histology; CDC, complement-dependent cytotoxicity; CTG, chronic transplant glomerulopathy; EM, electron microscopy; GFR, glomerular filtration rate; IFTA, interstitial fibrosis and tubular atrophy; IQR, interquartile range; KT, kidney transplantation; PRA, panel-reactive antibody; PTCML, peritubular capillary multilayering; SAB, Single Antigen Bead assays; SD, standard deviation; SLE, systemic lupus erythematosus. *From 101 available samples pre-transplantation. #From 46/47 biopsies (34 ABMRhDSApos, 12/13 ABMRhDSAneg).
The bold values represent those p-values that are statistically significant.